The “DC OK” LED indicator is connected directly across the output voltage through a current-limiting resistor. It is used to indicate the status of the power supply’s DC output.
DC OK LED ON Condition
The LED turns ON immediately when the power supply is switched on, as long as the output voltage is present and stable. In normal operation, this typically corresponds to the output voltage reaching a valid level (generally above the regulated threshold).
DC OK LED OFF Conditions
The LED will turn OFF under the following conditions:
- No AC input power The AC supply is turned off or not present.
- No or insufficient DC output The output voltage is not present or has dropped below the required operating level.
- LED circuit failure The LED or its internal circuit is faulty.
DC OK LED Blinking Condition
The LED will blink when the power supply enters hiccup protection mode, which is triggered by fault conditions such as overload or short circuit. This indicates the unit is in a protective restart cycle.